N, Ice and SOC

I did an experiment yesterday, while in park, listening to the radio with the AC on.
The SOC of the battery got down to 2 bars and ICE maintained that periodically, as we all would expect.
So, I decided to put the car in Neutral, and see if SOC would go down to 1 bar. I won't let it go lower than that. Yup, sure enough, it took a suprisingly long time, but it did go down to 1 bar, and no ICE startup.
I did have the parking brake engaged, and of course you have to be pressing on the main brake to go from Park to Neutral.

Once I got down to 1 bar, I put the car in Park. Immediately, ICE started up to charge the battery back to nominal level. It charged to 2 bars, but ICE kept on going.
Now here's the interesting part. While ICE was still running, I put the car back to Neutral. ICE continued, but settled on a really low idle. You could barely hear the ICE over the radio, and even without the radio, it was really low. Back in Park, and ICE 'idle' went back up to charge idle.
ICE kept going past 2 bars, and a bit into 3 blue bars before it finally quit. Once it quit, putting the car in Neutral did not start the ICE, again, as expected.

I wonder why ICE would continue to run when moved from Park to Neutral.

I did theorize one thing. Ever notice when SOC is low while crawling in traffic, ICE only seems to start when you are actually moving, where if it was in Park, the ICE would probably be running at that point?
I believe that as long as SOC is not dangerously low (anywhere within 2 bars), the HV ECU sees that you are in Drive with your foot on the brake, so you should be moving soon, so it tries to run ICE for propulsion as well as charge, rather than use it solely for charge. If SOC gets really, really low, then it would have no choice but to run ICE even if you are not moving.

 

First off, I agree the engine can't start when in Neutral, but there should be no reason it can't be shut off. Others have posted that they have 'encouraged' shutdown by putting the car in Neutral. However, as I wrote that last sentence, it may be they didn't hear the very low idle.

As for running in warmup, I doubt it. The engine had been running to charge, and engine stopped when in Park. I was considering putting it in Drive, probably should have. I suspect the engine would be shut off in Drive. Next time.

Usually when the car goes down to 2 bars when crawling in traffic, ICE will often stop when still in 2 bars. The range of bar two seems pretty wide, just as it is in bar 6.

As I stated in my original post, it probably doesn't charge to 6 bars in park, because it would be better to wait until you are actually driving to give it a full nominal charge, where ICE RPM would be greater.

By the way, during the experiment, AC was running, but was on the lower end of its output range, as the cabin was sufficiently cooled down, and I was parked under a tree for shade. ICE tends to almost not stop when AC is running full blast, as I have observed in crawling traffic.